The present invention relates to a sensor for sensing a rotation angle of a rotary object to be sensed, namely, a noncontact rotation angle sensor. More particularly, it relates to a rotation angle sensor which is provided with a magnetic sensitive element for sensing a magnetic flux varying with a rotor rotation and senses the rotor rotation angle in a noncontact manner.
For example, it relates to a rotation angle sensor for sensing a rotation angle of a throttle valve for a gasoline engine or a diesel engine, by using Hall elements, Hall ICs or the like. Also, the present invention relates to a throttle valve control device that is provided with such a rotation angle sensor.
Throttle position sensor using a rotation angle sensor senses a rotation angle of a throttle valve controlling an opening area of an air intake passage of a gasoline automobile, diesel automobile or the like. A conventional throttle position sensor is provided with a rotor section serving as a magnetic flux generating source, at one end of a throttle shaft.
The rotor section is provided with permanent magnets serving as a magnetic field generating source and yokes forming a magnetic passage, at a holder member fixed to the one end of the throttle shaft.
Also, the throttle position sensor is provided with a stator which is provided with a magnetic detecting gap through which the magnetic flux generated by the rotor section passes.
The Hall elements are mounted in the magnetic detecting (passing) gap of the stator.
The amount of the magnetic flux passing through the magnetic detecting gap is adapted to be varied according to the position of the rotor rotating together with the throttle shaft.
Thus, the Hall elements installed in the magnetic detecting gap are adapted to sense the magnetic flux which is varied by the rotation of the throttle shaft.
The Hall elements and a signal processing circuit section are integrally mounted to a resin-made housing to which the stator is fixed, or a cover member. An output from the sensor is supplied to an external unit through an electrical conductor and a connecter section. The conductor is insert-molded with the resin molded-member or cover member by resin-molding, and the connector section is molded together with the resin-made housing or the cover member by resin-molding.
There are Japanese Patent Application Laid-Open No. 2005-147926 and Japanese Patent Application Laid-Open No. 2001-289610 as prior arts related to this invention.